The purpose of this contract is to increase the usefulness and the availability to the scientific community of the large database and extensive serum collection of the Child Health and Development Studies (CHDS). The current contract proposal is a follow-on of a previous contract which was designed to develop a User's Guide to the CHDS Database. The User's Guide is completed and all of the database is now stored on magnetic tape. The data and the sera that comprise the CHDS resource were collected from mothers, fathers, and offspring of 15,000 families during 20,754 pregnancies from 1959-1967 and from the families and offspring until 1979. The rationale for this enormous undertaking is to increase our understanding of how genetic, physiologic, medical and environmental factors of parents affect the health and development of their offspring. The CHDS data files and serum collection comprise a national resource which needs to be maintained in a useful state to serve investigators from many scientific disciplines for years to come. An important aspect of the CHDS study population lies in its potential for future studies in conjunction with the extant data base and serum collection. A central task of the current proposal is to update the address file with current addresses of the CHDS study population. The CHDS serum collection consists of 70,000 samples taken from 18,400 pregnant women, 10,000 husbands, and 3,000 newborns. The samples were drawn for blood typing, routine laboratory chemistry, and for long-term storage at -20degreesC for future research. A second important task of the current contract is to unite the extensive CHDS serum collection in one safe place for the first time in its 28-year history. The extensive records of the serum collection document the circumstances of blood drawing, subject state and preparation, method of serum separation and storage, and the history of use of each sample by various investigators and the purpose of their investigations. The third major task of the current contract is to transfer the accumulated information about each sample of the extensive serum collection from notebooks and handwritten ledgers to magnetic data tape in order to improve the usefulness of the unique serum collection.